Biomolecules & Organic Inorganic Compounds

• Biomolecules


  Chemicals or molecules present in living organisms
• Biomolecules are compounds of carbon
• Cellular pool


  Sum total of different types of biomolecules, compounds, and ions present in a cell
• Carbon is the most versatile and the most predominant element of life
• 2 Types of Biomolecules

  • Micro molecules
  • Macro molecules
• Micro molecules


  Small-sized, low molecular weight (Between 18 and 800 daltons), found in acid soluble pool
• Macro molecules


  Large-sized, high molecular weight (Above 10,000 daltons), found in the acid insoluble pool
• Macro molecules


  • Carbohydrates
  • Lipids
  • Proteins
  • Nucleic acids
• The Major Complex Biomolecules of Cells

  • Protein
  • DNA
  • RNA
  • Polysaccharide
  • Lipids
• Protein


  Building block: Amino acid, Major functions: Basic structure and function of cell
• DNA


  Building block: Deoxyribonucleotide, Major functions: Hereditary information
• RNA


  Building block: Ribonucleotide, Major functions: Protein synthesis
• Polysaccharide


  Building block: Monosaccharide, Major functions: Storage form of energy
• Lipids


  Building block: Fatty acids & glycerol, Major functions: Storage form of energy to meet long term demands
• Carbohydrates are the most abundant organic molecules in nature
• Carbohydrates


  The term is derived from the French term "hydrate de carbone" i.e. hydrate of carbon, defined as organic substances having C, H & O wherein H & O are in the ratio 2:1 as found in H2O
• Functions of Carbohydrates


  • Most abundant source of energy (4 cal/g)
  • Precursors for many organic compounds (fats, amino acids)
  • Present as glycoproteins and glycolipids in the cell membrane and functions such as cell growth and fertilization
  • Present as structural components like cellulose in plants, exoskeleton of some insects, cell wall of microorganisms
  • Storage form of energy (glycogen) to meet energy demands of the body
• 3 Types of Carbohydrates

  • Monosaccharides
  • Oligosaccharides
  • Polysaccharides
• Monosaccharides


  Basic units of carbohydrates that cannot be hydrolysed into smaller units
• Monosaccharides based on number of C-atoms

  • Trioses
  • Tetroses
  • Pentoses
  • Hexoses
  • Heptoses
• Aldoses


  Monosaccharides with an aldehyde (CHO) functional group
• Ketoses


  Monosaccharides with a ketone (C=O) functional group
• Oligosaccharides


  They can be further hydrolyzed, including disaccharides, trisaccharides, and tetrasaccharides
• Polysaccharides


  Non-crystalline, non-soluble in water, tasteless, on hydrolysis gives monomers of monosaccharides, also called glycans, made up of repeating units of monosaccharides held by glycosidic bonds
• 2 Types of Polysaccharides

  • Homoglycans
  • Heteroglycans
• Homoglycans


  Made up of only one type of monosaccharide monomers, e.g. starch, glycogen, cellulose
• Heteroglycans


  Made up of condensation of two or more types of monosaccharides, e.g. Hyaluronic acid, agar, chitin, peptidoglycans
• Starch


  Carbohydrate reserve of plants and the most important dietary source for animals, homopolymer made up of glucose units, combination of amylose and amylopectin
• Glycogen


  Carbohydrate reserve in animals, also called animal starch, high concentration in liver, muscles and brain, also found in plants that do not have chlorophyll (yeast and fungi), glucose is the repeating unit
• Cellulose


  Occurs exclusively in plants and is the most abundant organic substance in plant kingdom, predominant constituent of plant cell wall, totally absent in animals
• Chitin


  Second most abundant organic substance, complex carbohydrate of heteropolysaccharide type, found in the exoskeletons of some invertebrates like insects and crustaceans, provides both strength and elasticity
• Simple Lipids


  • Neutral/True Fats
  • Waxes
• Neutral/True Fats


  Esters of fatty acids with glycerol, made up of C, H, & O but O is less
• Waxes


  Lipids which are long chain saturated fatty acids and a long chain saturated alcohol of high molecular weight other than glycerol, examples include beeswax, lanolin, sebum, cerumen, plant wax, paraffin wax
• Proteins are the most abundant organic molecules of the living system, forming about 50% of the dry weight of the cell, and are the most important for the architecture and functioning of the cell
• Proteins


  Polymers of amino acids, on complete hydrolysis yield amino acids, there are 20 standard amino acids which are repeatedly found in the structure of proteins
• Collagen is the most abundant animal protein, Rubisco is the most abundant plant protein
• Protein Synthesis


  Is controlled by DNA
• Amino Acids


  Organic compounds having 2 functional groups (-NH2) which is basic and (-COOH) which is acidic, examples include glycine and alanine, physical and chemical properties are due to amino, carboxyl and R functional groups, can be classified into 7 groups: neutral, acidic, basic, S-containing, alcoholic, aromatic, and heterocyclic
• Classifications of Proteins


  • Structural proteins
  • Enzymatic proteins
  • Transport proteins
  • Hormonal proteins
  • Contractile proteins
  • Storage proteins
  • Genetic proteins
  • Defense proteins
  • Receptor proteins